Republicans have dismissed many of the programs as unnecessary, unpopular or too expensive, and appear to be lining up to oppose the plans outright in Congress unless Democrats agree to scale them back significantly.

Even if they do become law, though, academics who have shaped the debate over reparations insist Mr. Biden’s plans are not a substitute. William A. Darity Jr., a professor of public policy at Duke University who has written a book on reparations, said such proposals “are kind of shadow boxing at the issue.”

“If this is about the full ramifications on Black wealth, about the destruction of entire businesses or neighborhoods, or the deprivation and loss of land, then we are talking about numbers that are far beyond the reach of what are relatively small programmatic initiatives,” Mr. Darity said.

Mr. Darity’s vision of reparations primarily focuses on closing the wealth gap between African-Americans and white people, something that he estimates would take $10 trillion or more in government funds, an enormous figure that alienates lawmakers in both parties.

Roy L. Brooks, a law professor at the University of San Diego who has also written on the issue, argued that the purpose of reparations should be viewed neither as primarily monetary nor as something that could be dealt with in the course of normal policymaking.

“You miss an opportunity to really bring home to the American people the enormity of the atrocity that was visited upon African-Americans for 250 years of slavery and then another 100 years of Jim Crow,” he said.

Opponents argue that the wrongs of slavery are simply too far past and too diffuse to be practically addressed now. They question why taxpayers, many of whom came to the United States long after slavery ended, should foot a potentially large bill for payments to Black Americans — and whether such payments would be a benefit at all.

“Reparation is divisive. It speaks to the fact that we are a hapless, hopeless race that never did anything but wait for white people to show up and help us — and it’s a falsehood,” Representative Burgess Owens, Republican of Utah and a descendant of slaves, said during the debate on Wednesday. “It’s demeaning to my parents’ generation.”

Mr. Owens has compared the idea of reparations to a “redistribution of wealth or socialism,” arguing that what Black Americans need is for government to get out of the way as they sought to pull themselves up like generations before them.

Some Democrats share those views, and others are skittish about embracing a bill they fear Republicans would weaponize against them by portraying it as a radical effort to use government to enforce a politically correct agenda.